A convenient and common way of mounting a gas turbine engine on an aircraft is to suspend the engine from a pylon mounted on the underside of the aircraft's wing. For reasons of aerodynamic efficiency, the engine is enclosed in a nacelle; large holes being provided at the ends of the nacelle to respectively accommodate the engine air inlet and exhaust nozzle.
Typically, the engine is attached to the pylon and the nacelle is mounted either from the engine or directly from the pylon. In either arrangement, the nacelle intake and final nozzle portions are directly attached to the engine. This results in loads being imposed upon the engine's casing which are additional to those which result from normal engine operation. As a consequence the engine's casings have to be made stronger, and therefore heavier, than would otherwise be the case.
In GB2046193A there is disclosed a gas turbine engine installation in which the nacelle, rather than the engine which it contains, supports the engine air inlet and exhaust systems. The nacelle is divided into upper and lower parts, both of which provide engine support. The lower nacelle part is adapted to pivot away from the upper part to provide engine access. However to achieve this, the interconnections between the lower cowling part and the engine have to be disconnected. This prolongs and complicates the process of engine access and removal. Moreover, the interconnections between the engine and nacelle, particularly those at the rearward end of the engine, tend to obstruct air flow if the gas turbine engine is of the ducted fan type.